It's the custom '67 Mustang from the 2014 mainline Hot Wheels. This is the very rare black MC5 wheel variation. It's my holy grail for several different reasons. The first reason is because it was hard for me to find since there are not very many around. The second reason is just because I like the car. The wheels make this Mustang look like a classic muscle car. The third, and final reason is, because this Mustang was the missing piece for me to have a complete set of the subset of the Mustang 50th Anniversary segment of the 2014 Hot Wheels.
So yeah, what's your holy grail? Just comment below!